One of the biggest problems with pizza delivery or carry out boxes is that during transport the pizza crust loses crispness and becomes soggy. This obviously reduces the quality of the product which is no longer as good as if it was fresh out of the oven. In particular, the taste, bite, texture, and overall perception of the product are often compromised. The pizza chef may also become frustrated because the diminished quality of the product at the time of consumption does not represent the chef's level of skill and potential cutting edge talent.
The following factors are believed to at least partially contribute to this issue. First, the steam released from the hot and watery ingredients is essentially confined inside the closed box and absorbs back into the crust making it soggy. Such an issue may be further exacerbated when the box is transported in delivery bags which allow for little or no ventilation. Allowing quick release of almost all of the steam from a pizza is not a favorable solution because the heat would escape together with the steam, resulting in a cold product. For most customers and restaurants, this is not a positive compromise. On the other hand, allowing the steam and heat to escape from the box too slowly in order to retain some heat inside may provide warm or even hot pizza, but it will likely still become soggy.
Second, when the pizza is cut prior to delivery (as is common in the industry), liquids such as oils and juices can escape the pizza to collect at the bottom of the box. In such a scenario, the pizza is essentially sitting on a wet surface. Consequently, the crust ends up absorbing the liquids like a sponge which again renders it soggy.
To date, attempts to address the issue of soggy pizza crusts have been largely unsatisfactory. For instance the interior of a box may be lined with a heat reflective material such as foil. The idea here is to allow steam to escape quickly and relying on the heat reflective or retaining inner surface to maintain heat in the box. However, this technique has limitations. For instance, the liquids from the pizza can still pool below the crust and reabsorb into the pizza. Also, the additional reflective material and production steps required may drastically increase the cost. Most pizza producers have a sensitive profit margin and therefore are not likely to view this as a viable solution.
Yet another attempt involves a pizza box design with ventilated top and bottom surfaces. For example, one design includes staggered cutouts across three layers of the cardboard material to allow air and steam to pass through the center corrugated layer to reach the exterior of the box. Several problems exist here. When multiple boxes are stacked, the path of heat or steam released through the top of a box can obstructed by the box above it. As yet another issue, the steam that escapes from the top may flow into the box directly above it thereby contributing to the very issue the design seeks to avoid. Finally, the liquids dripping to the bottom of the box can pass right through the ventilated bottom and into the box below it. To make matters worse, the box can stain any surface it sits on because the liquids diffuse from the bottom. Of course, placing grease proof paper at the bottom of the box defeats the purpose of a ventilated bottom as it prevents steam from exiting the bottom.
Elongated pores in the shape of stripes on the bottom of the box have also been suggested. Such a design is likely to suffer from uneven ventilation since the pores are not uniformly laid out. Similar to other suggested designs, the ventilation here may also be obstructed when such boxes are stacked or lined with grease paper. Additionally, these boxes may also leak the liquids, particularly when housing cut pizza.
The above solutions appear even less viable when considering common industry and customer practices. For instance, pizza boxes are often delivered using a pizza bag which provides little or no ventilation. As such, during delivery a box, or stack of boxes, may be maintained for as long as 30 minutes in a moisture rich environment that can exacerbate the problem with soggy crusts. Customer carry out is also problematic because the box would have to be held up during transport to allow ventilation from the bottom. In other words, unless a single box is held up during the entire time between purchase and consumption, it will invariably rest on another surface during transport for a significant period of time. Again this frustrates ventilation from the bottom of the box.
To date, attempts at addressing the problems discussed above have been unsatisfactory. Many of the designs provide little or no improvement. Moreover, some also require special circumstances in order to provide proper venting or to prevent leaking.